In fishing, especially on lakes, it is common to use a boat equipped with two outboard motors, one a large, motor for high speed propulsion, and the other a smaller motor for propelling the boat at low speed while trolling.
When trolling, it is important to be able to steer the boat both to avoid obstacles, and to maneuver the boat to circle schools of fish and to make more effective use of fishing rods and fish-retrieval nets. The boat can be steered by manipulation of a tiller attached to the battery-powered motor, but this requires the operator to be remain seated at the stern where he may have difficulty spotting fish and managing fishing equipment. It is desirable to be able to steer the boat from any of several locations on the boat, and to this end various remote steering devices have been utilized. One such device is described in U.S. Pat. No. 7,666,039, granted Feb. 23, 2010, the disclosure of which is incorporated by reference. In U.S. Pat. No. 7,666,039, a steering control is attached to one end of the tilt tube of an outboard motor. A linear actuator in the steering control is connected to a rod that extends through the tilt tube. The other end of the rod is linked to the motor, and linear actuator pushes and pulls the rod, steering the motor.
The linear actuator comprises a rotating electric motor that operates a worm gear in mesh with a toothed wheel that in turn operates a pinion in mesh with a rack that extends into the tilt tube. The rack needs to be long enough to steer the outboard motor through its full range, and the dimension of the steering control housing in the direction of rack movement needs to be sufficient to accommodate the rack when the rack is fully withdrawn.
It is convenient and desirable to locate the steering control described above between the larger motor and the smaller trolling motor. However, the large motor will normally be located at the center of the transom and the trolling motor offset to one side. Especially in a small boat having a narrow transom, the trolling motor will be positioned close to the large motor so that no part of the steering control extends beyond the ends of the transom where it could be damaged easily by contact with pilings, buoys or the like. In a boat having a wider transom, the trolling motor is also preferably positioned as close as possible to the center of the transom in order to minimize the drag caused when the trolling motor is steered to counteract yaw. The space required for a rack and pinion-type steering control makes it difficult to achieve these objectives. If the conventional rack and pinion-type steering control is positioned on the opposite end of the tilt tube of the trolling motor, the steering linkage then takes up a similarly large amount of space between the motors.